Water absorbing pad, water-absorbing product and diaper using water-absorbing pad, and method for washing the same

Abstract

A paper diaper using an water-absorbing polymer is superior in absorbency/water-retaining performance to a cloth diaper, but it has the drawback that it generates garbage and is expensive. An water-absorbing pad is formed by allowing an water-absorbing polymer which is dispersed, dissolved or melted or the crosslinks of which are broken in an electrolytic aqueous solution to be retained by a water soluble material. An water-absorbing product is produced by interposing the water-absorbing pad thus formed between sheets of cloth or other materials. The water-absorbing pad secured within the product is dissolved when washed with an electrolytic aqueous solution, and the product itself is reusable.

What is claimed is:  
     
       1. A water-absorbing pad comprising: 
       a water-absorbing polymer having a characteristic such that the polymer is dispersed or dissolved in an electrolytic aqueous solution; and  
       a water soluble material in a flat sheet form for wrapping the polymer to retain the same therein so that when the water-absorbing pad is held in a sufficient amount of the electrolytic aqueous solution, the water-absorbing pad is quickly dispersed or dissolved in the aqueous solution.  
     
     
       2. The water-absorbing pad according to  claim 1 , wherein said water-absorbing polymer has crosslinks therein, said crosslinks being broken in the electrolytic aqueous solution. 
     
     
       3. The water-absorbing pad according to  claim 2 , wherein said water-absorbing polymer is a crosslinked polyacrylate resin or a crosslinked polystarch acrylate resin. 
     
     
       4. The water-absorbing pad according to  claim 2 , wherein said water soluble sheet is a sheet of water soluble paper. 
     
     
       5. The water-absorbing pad according to  claim 2 , wherein said water soluble sheet is a water soluble non-woven fabric. 
     
     
       6. The water-absorbing pad according to  claim 1 , further comprising an electrolytic substance therein. 
     
     
       7. The water-absorbing pad according to  claim 1 , further comprising an adhesive for gluing said water soluble sheet and an electrolytic substance mixed in the adhesive. 
     
     
       8. A water-absorbing product, comprising the water-absorbing pad as recited in  claim 1  and sheets, the water-absorbing pad being interposed between the sheets. 
     
     
       9. The water-absorbing product according to  claim 8 , wherein at least one of the sheets between which said water-absorbing pad is interposed is made of a material to allow moisture to easily permeate from its surface-side to a water-absorbing pad-side but prevent the moisture to permeate from the water-absorbing pad-side to the surface-side. 
     
     
       10. The water-absorbing product according to  claim 9 , further comprising a waterproof sheet attached to an outside of the other of the sheets between which said water-absorbing pad is interposed. 
     
     
       11. The water-absorbing product according to  claim 8 , wherein said sheets for enclosing the water-absorbing pad have an openable side with a mark. 
     
     
       12. The water-absorbing product according to  claim 8 , wherein said sheets for wrapping the water-absorbing pad includes overlapped portions constituted of a set of at least two sheets sewed together by seams, and said seams are made so as not to overlap with each other when said sheets are folded. 
     
     
       13. The water-absorbing product according to  claim 8 , wherein said sheets for wrapping the water-absorbing pad includes a pad mount section on which said water-absorbing pad is placed, and four flaps around the pad mount section, a pair of flaps in the four flaps being made shorter in width than said pad mount section. 
     
     
       14. A diaper comprising the water-absorbing product as recited in  claim 8  and diaper sheets made of diaper materials which are used together with the water-absorbing product. 
     
     
       15. A diaper comprising the water-absorbing pad as recited in  claim 1  and sheets of diaper materials covering the water-absorbing pad. 
     
     
       16. The diaper according to  claim 15 , wherein one of the sheets which partly covers the water-absorbing pad and is brought into contact with a skin is made of a material as to allow moisture to easily permeate from its surface-side to a water-absorbing pad-side but prevent moisture to permeate from the water-absorbing pad-side to the surface-side. 
     
     
       17. The diaper according to  claim 14 , wherein said diaper sheets for wrapping the water-absorbing pad include an openable side with a mark. 
     
     
       18. The diaper according to  claim 14 , wherein said diaper sheets for wrapping the water-absorbing pad include overlapped portions constituted of a set of at least two sheet portions sewed together by seams, and said seams are made so as not to overlap with each other when said diaper sheets are folded. 
     
     
       19. The diaper according to  claim 14 , wherein said diaper sheets for wrapping the water-absorbing pad include a pad mount section on which said water-absorbing pad is placed, and four flaps around the pad mount section, a pair of flaps in the four flaps being made shorter in width than said pad mount section. 
     
     
       20. The diaper according to  claim 14 , further comprising a diaper cover, said diaper sheets being detachable from the diaper cover. 
     
     
       21. The diaper according to  claim 14 , further comprising a diaper cover, said diaper sheets being integrally attached to the diaper cover. 
     
     
       22. The diaper according to  claim 20 , further comprising a fastener attached to said diaper cover to hold the diaper cover in a shape of a panty, and a strip of raised cloth which adheres to the fastener provided in an immediate vicinity of the fastener, a fastener-provided portion of the diaper cover unfolded from the shape of a panty being folded to adhere the fastener to the strip of raised cloth. 
     
     
       23. The diaper according to  claim 20 , further comprising a piece of fabric to prevent said set of diaper sheets from being dislocated, said piece of fabric being attached to an inside of said diaper cover. 
     
     
       24. A method for washing a water-absorbing product composed of a water-absorbing pad formed of a water-absorbing polymer which is dispersed or dissolved in an electrolytic aqueous solution, and sheets between which the pad is interposed, said method comprising the step of washing the water-absorbing product with the water-absorbing pad interposed between the sheets by the electrolytic aqueous solution so that the sheets with the water-absorbing pad is quickly dispersed or dissolved in the aqueous solution. 
     
     
       25. The method for washing a water-absorbing product according to  claim 24 , wherein the water-absorbing product is washed with a detergent previously mixed with an electrolytic substance. 
     
     
       26. A method for washing a diaper composed of a water-absorbing pad formed of a water-absorbing polymer which is dispersed or dissolved in an electrolytic aqueous solution, and sheets between which the pad is interposed, said method comprising the step of washing the diaper with the water-absorbing pad interposed between the diaper sheets by the electrolytic aqueous solution so that the sheets with the water-absorbing pad is quickly dispersed or dissolved in the aqueous solution. 
     
     
       27. The method for washing a diaper according to  claim 26 , wherein the diaper is washed with a detergent previously mixed with the electrolytic substance. 
     
     
       28. The method for washing a diaper according to  claim 26 , wherein the diaper has a diaper cover to which said set of diaper sheets is attached, and the diaper is washed with the set of diaper sheets between which said water-absorbing pad is interposed. 
     
     
       29. The method for washing a diaper according to  claim 28 , wherein said diaper cover includes a fastener attached to said diaper cover to hold the diaper in a shape of a panty, and a strip of raised cloth provided in an immediate vicinity of the fastener, the diaper in a condition that a fastener-provided portion of the diaper cover unfolded from the shape of a panty is folded to adhere the fastener to the strip of raised cloth being washed.